te mātauranga matū, kaupae 2, 2015(g), ki te whakawera wai, e ai ki te hoahoa i raro. ka inea e...

911645

2SUPERVISOR'S USE ONLY

9 11 6 4 M

© Mana Tohu Mātauranga o Aotearoa, 2015. Pūmau te mana. Kia kaua rawa he wāhi o tēnei tuhinga e whakahuatia ki te kore te whakaaetanga tuatahi a te Mana Tohu Mātauranga o Aotearoa.

MĀ TE KAIMĀKA ANAKE

TAPEKE

Te Mātauranga Matū, Kaupae 2, 201591164M Te whakaatu māramatanga ki te honohono,

te hanga, ngā āhuatanga me ngā huringa pūngao

9.30 i te ata Rāhina 23 Whiringa-ā-rangi 2015 Whiwhinga: Rima

Paetae Kaiaka KairangiTe whakaatu māramatanga ki te honohono, te hanga, ngā āhuatanga me ngā huringa pūngao.

Te whakaatu māramatanga hōhonu ki te honohono, te hanga, ngā āhuatanga me ngā huringa pūngao.

Te whakaatu māramatanga matawhānui ki te honohono, te hanga, ngā āhuatanga me ngā huringa pūngao.

Tirohia mēnā e rite ana te Tau Ākonga ā-Motu (NSN) kei runga i tō puka whakauru ki te tau kei runga i tēnei whārangi.

Me whakamātau koe i ngā tūmahi KATOA kei roto i tēnei pukapuka.

He taka pūmotu kua whakaritea ki te Rau Rauemi L2-CHEMMR.

Mēnā ka hiahia whārangi atu anō koe mō ō tuhinga, whakamahia ngā whārangi wātea kei muri o tēnei pukapuka, ka āta tohu ai i te tau tūmahi.

Tirohia mēnā e tika ana te raupapatanga o ngā whārangi 2 – 21 kei roto i tēnei pukapuka, ka mutu, kāore tētahi o aua whārangi i te takoto kau.

ME HOATU RAWA KOE I TĒNEI PUKAPUKA KI TE KAIWHAKAHAERE Ā TE MUTUNGA O TE WHAKAMĀTAUTAU.

Te Mātauranga Matū 91164M, 2015

MĀ TE KAIMĀKA

ANAKE

TŪMAHI TUATAHI

(a) TātuhiatehangangaaLewis(hoahoatongiirahiko)mōiarāpoingotaewhaiakenei:

Te rāpoi ngota O2 OCl2 CH2O

Hanganga a Lewis

(b) Kataeaengāngotawarotehonokingāngotarerekēkiaputaaingāmomopūhuirerekēmaha.

EwhakaatuanatetūtohiewhaiakeitehangangaLewismōngārāpoingotaeruaewhaiwaroanaheingotapū,teCCl4meteCOCl2.Hererekēngākokihonongamengāāhuaoēneirāpoingota.

Te rāpoi ngota

CCl4 COCl2

Hanganga a Lewis Cl C Cl

Cl

ClCl C Cl

O

AromātaihiatehangangaLewisoiarāpoingotaheiwhakatauitetakehererekēngākokihonongamengāāhua.

Itōtuhingamewhakauruekoe:

• tekokihonongaāwhiwhiiiarāpoingota

• teāhuaoiarāpoingota

• ngātakeewhakariteaiiteāhuametekokihonongamōiarāpoingota.

2

QUESTION ONE

(a) DrawtheLewisstructure(electrondotdiagram)foreachofthefollowingmolecules.

Molecule O2 OCl2 CH2O

Lewis structure

(b) Carbonatomscanbondwithdifferentatomstoformmanydifferentcompounds.

ThefollowingtableshowstheLewisstructurefortwomoleculescontainingcarbonasthecentralatom,CCl4andCOCl2.Thesemoleculeshavedifferentbondanglesandshapes.

Molecule CCl4 COCl2

Lewis structure Cl C Cl

Cl

ClCl C Cl

O

EvaluatetheLewisstructureofeachmoleculetodeterminewhytheyhavedifferentbondanglesandshapes.

Inyouranswer,youshouldinclude:

• theapproximatebondangleineachmolecule

• theshapeofeachmolecule

• factorsthatdeterminetheshapeandbondangleforeachmolecule.

3

Chemistry 91164, 2015

ASSESSOR’S USE ONLY


MĀ TE KAIMĀKA

ANAKE

(c) HererekēngārāpoingotaoBeCl2meBF3itemeakāoreitetinorawakangāirahikomōngāngotapū,BemeB,kiawhaiangaāpitikī.KuawhakaaturiangāhangangaaLewisiraronei.

Cl Be Cl F B FF

Heōritetepitoruatanga1ongārāpoingotaerua.

Porohitatiatekupuewhakaahuaanaitepitoruatangaoauarāpoingota.

pitorua pitokore

Parahautiatōkōwhiringa.

1tōranga

4

(c) BeCl2andBF3areunusualmoleculesbecausetherearenotenoughelectronsforthecentralatoms,BeandB,tohaveafullvalenceshell.TheirLewisstructuresareshownbelow.

Cl Be Cl F B FF

Bothmoleculeshavethesamepolarity.

Circlethewordthatdescribesthepolarityofthesemolecules.

polar non-polar

Justifyyourchoice.

5




MĀ TE KAIMĀKA

ANAKE

(d) Katauhohetehaurehuwaiwaroruaewaro,C2H4(g),kitehaurehupūkane,Br2(g),eaikitewhāriteewhaiake.

C C (g) + Br Br (g) H C C H (g)H

H

H H H

Br BrH

Tātaihiatehuringahāwera,∆rH°,mōtetauhohengaiwaengaingāhaurehuwaiwaroruaewarometepūkane,eaikingāhāwerahonongatohariteirotoitetūtohiiraro.

Whakaaturiakatoatiaōmahingametewhakauruingāwaehāngaikitōwhakautu.

Hononga Hāwera hononga toharite / kJ mol–1

Br–Br 193C–C 346C=C 614C–Br 285C–H 414

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(d) Ethenegas,C2H4(g),reactswithbrominegas,Br2(g),asshownintheequationbelow.

C C (g) + Br Br (g) H C C H (g)H

H

H H H

Br BrH

Calculatetheenthalpychange,∆rH°,forthereactionbetweenetheneandbrominegases,giventheaveragebondenthalpiesinthetablebelow.

Showyourworkingandincludeappropriateunitsinyouranswer.

Bond Average bond enthalpy / kJ mol–1

Br–Br 193C–C 346C=C 614C–Br 285C–H 414

7




MĀ TE KAIMĀKA

ANAKE

TŪMAHI TUARUA

(a) Keirotoingāwhakamahanaringatētahimehangatinopūhakerawaotekonutaiehākawa2 (sodiumethanoate),ā,inawhakahohea,kawhātioatametewhakaputawera.

Porohitatiatekupuewhakaahuapaianaitēneitauhohenga.

putawera pauwera

Homaitētahipūtakemōtōkōwhiringa.

(b) (i) Whakanaohiaaitekūhukairotoingātipuitewāoteahotakakameinatauhohetehauhā3,CO2(g),metewai,H2O(),kiaputaaitekūhuka,C6H12O6(aq),metehaurehuhāora,O2(g).Kataeatewhakaatutetauhohengaahotakakamemātewhāriteewhaiake:

6CO2(g) + 6H2O() → C6H12O6(aq) + 6O2(g)∆rH°=2803kJmol–1

Porohitatiatekupuewhakaahuapaianaitēneitauhohenga.

putawera pauwera

Homaitētahipūtakemōtōkōwhiringa.

(ii) Tātaihiaehiatenuiotepūngaokawhenumitia,kaputarāneiirotoitetauhohengaahotakakamemēnākatinotauhohete19.8gotehauhā,CO2(g),kitewaiinati,H2O(),kiaputatekūhuka,C6H12O6(aq),metehaurehuhāora,O2(g).

Whakaaturiakatoatiaōmahingametewhakauruingāwaehāngaikitōwhakautu.

M(CO2)=44.0gmol–1

2konutaiwinika3warohāora-rua

8

QUESTION TWO

(a) Handwarmerscontainasupersaturatedsolutionofsodiumethanoatewhich,whenactivated,crystallisesandreleasesheat.

Circlethetermthatbestdescribesthisreaction.

exothermic endothermic

Giveareasonforyourchoice.

(b) (i) Glucoseismadeinplantsduringphotosynthesiswhencarbondioxidegas,CO2(g),andwater,H2O(),reacttoproduceglucose,C6H12O6(aq),andoxygengas,O2(g).Thephotosynthesisreactioncanberepresentedbythefollowingequation:

6CO2(g) + 6H2O() → C6H12O6(aq) + 6O2(g)∆rH°=2803kJmol–1

Circlethetermthatbestdescribesthisreaction.

exothermic endothermic

Giveareasonforyourchoice.

(ii) Calculatehowmuchenergyisabsorbedorreleasedinthephotosynthesisreactionif19.8gofcarbondioxidegas,CO2(g),reactscompletelywithexcesswater,H2O(),toformglucose,C6H12O6(aq),andoxygengas,O2(g).

Showyourworkingandincludeappropriateunitsinyouranswer.

M(CO2)=44.0gmol–1

9




MĀ TE KAIMĀKA

ANAKE

(c) Kawhakamahiatētahitōpuniitiwhaihaurehupūwaro,C4H10(g),kitewhakawerawai,eaikitehoahoairaro.Kaineaetētahiākongatehuringapaemahanairotoitewaimetetātaiitengingihaotepūwaro3.65g,kawhakaputainate106kJotewera.

HAUREHU

Thermometer

Metal can

Water

Tap

Small camping gas ‘bottle’

Inepaemahana

Kēnemaitai

Wai

Kōrere

‘Pātara’haurehupuniiti

Ewhakaaturiaanatetauhohengamōtengingihaotepūwarokitewhāriteiraro.

2C4H10(g) + 13O2(g) → 8CO2(g) + 10H2O()

(i) Tātaihiatepanonihāweranoa(∆rH)mōtēneitauhohenga,mātewhakamahiingāinengaorunga.

M(C4H10)=58.0gmol–1

10

(c) Asmallcampstovecontainingbutanegas,C4H10(g),isusedtoheatsomewater,asshowninthediagrambelow.Astudentmeasuresthetemperaturechangeinthewaterandcalculatesthatwhen3.65gofbutaneiscombusted,106kJofheatisreleased.

GAS

Thermometer

Metal can

Water

Tap

Small camping gas ‘bottle’

Thereactionforthecombustionofbutaneisshownintheequationbelow.

2C4H10(g) + 13O2(g) → 8CO2(g) + 10H2O()

(i) Calculatetheenthalpychange(∆rH)forthisreaction,basedontheabovemeasurements.

M(C4H10)=58.0gmol–1

11




MĀ TE KAIMĀKA

ANAKE

(ii) Kotehuringahāweraewhakaaetiaanamōtetauhohengangingihaotehaurehupūwaro,C4H10(g),he∆r H=–5754kJmol

–1.

Whakamāramahiatetakehererekēteotingaitātaihiaekoeitewāhanga(c)(i)kiteuaraewhakaaetiaana.

MehomaiekoengātakeeRUAnekeaturāneiitōtuhinga.

(iii) Whakaotihia,mengātapangaanō,tehoahoapūngaomōtengingihaotehaurehupūwaroewhakaatuanaingāpūmatūhohe,ngāhua,metehuriotehāwera.

Energy

Reaction proceeds

Pūngao

Haeretonutetauhohenga

12

(ii) Theacceptedenthalpychangeforthecombustionreactionofbutanegas,C4H10(g),is∆rH=–5754kJmol

–1.

Explainwhytheresultyoucalculatedinpart(c)(i)isdifferenttotheacceptedvalue.

Inyouranswer,youshouldincludeatleastTWOreasons.

(iii) Complete,includinglabels,theenergydiagramforthecombustionofbutanegasshowingreactants,products,andthechangeinenthalpy.

Energy

Reaction proceeds

13




MĀ TE KAIMĀKA

ANAKE

(iv) Hekorawhaitaketehaurehupūwaroitemeainangingihatia,kaputahepūngao.

Whakamāramahiatetakeheahaiwhakaputainaaihepūngaoitēneitauhohenga,eaikitewaihangametewāwāhihononga.

Kāoreehiahiatiaanahetātaitanga.

14

(iv) Butanegasisausefulfuelbecausewhenitundergoescombustion,energyisreleased.

Explainwhyenergyisreleasedinthisreaction,intermsofmakingandbreakingbonds.

Nocalculationsarerequired.

15




MĀ TE KAIMĀKA

ANAKE

TŪMAHI TUATORU

(a) Whakaotihiatetūtohiiraromātekīmaiitemomototoka,temomokorakorakeiroto,mengātōpanakumeiwaengaingākorakoraiiatotoka.

Totoka Tūmomo totoka Tūmomo korakora Ngā tōpana kume i waenga korakora

Cu(s)(konukura)

PCl3(s)(pūtūtaewhetū

pūhaumāota-toru)

SiO2(s)(takawaihāora-rua)

KCl(s)(konurehupūhaumāota)

(b) Hewēitepaemahanarūmatepūtūtaewhetūpūhaumāota-toru,PCl3,ā,kāoreekawehikoana.

Whakamāramahiamaiēneikitengaeruaeaikingākorakora,hanganga,metehonohonootePCl3.

16

QUESTION THREE

(a) Completethetablebelowbystatingthetypeofsolid,thetypeofparticle,andtheattractiveforcesbetweentheparticlesineachsolid.

Solid Type of solid Type of particle Attractive forces between particles

Cu(s)(copper)

PCl3(s)(phosphorustrichloride)

SiO2(s)(silicondioxide)

KCl(s)(potassiumchloride)

(b) Phosphorustrichloride,PCl3,isaliquidatroomtemperature,anddoesnotconductelectricity.

Explainthesetwoobservationsintermsoftheparticles,structure,andbondingofPCl3.

17




MĀ TE KAIMĀKA

ANAKE

(c) Whakaarohiaiatotokaotekonukara,Cu,takawaihāora-rua,SiO2,metekonurehupūhaumāota,KCl.

Whakaotihiatetūtohiiraromātetautohukeiēheaoēneitotokangāāhuatangaōkikoerārangitiaana.

Ngā āhuatanga ōkiko Totoka

Kāoretetotokaerewairotoitewai,ā,hemāngohe.

Herewatetotokairotoitewai,ā,eharaitemāngohe.

Kāoretetotokaerewairotoitewai,ā,eharaitemāngohe.

ParahautiaōkōwhiringaeRUAeaikingākorakora,hanganga,metehonongaoēneitotoka.Kawhakaaetiatewhakamahihoahoaheitautokoitōtuhinga.

18

(c) Considereachofthesolidscopper,Cu,silicondioxide,SiO2,andpotassiumchloride,KCl.

Completethetablebelowbyidentifyingwhichofthesesolidshavethelistedphysicalproperties:

Physical properties Solid

Thesolidisinsolubleinwaterandismalleable.

Thesolidissolubleinwaterandisnotmalleable.

Thesolidisinsolubleinwaterandisnotmalleable.

JustifyTWOofyourchoicesintermsoftheparticles,structure,andbondingofthesesolids.Youmayusediagramsinyourjustification.

19




MĀ TE KAIMĀKA

ANAKETAU TŪMAHI

He whārangi anō ki te hiahiatia.Tuhia te (ngā) tau tūmahi mēnā e tika ana.

20

21



QUESTION NUMBER

Extra paper if required.Write the question number(s) if applicable.

911

64

M

Level 2 Chemistry, 201591164M Demonstrate understanding of bonding,

structure, properties and energy changes

9.30 a.m. Monday 23 November 2015 Credits: Five

Achievement Achievement with Merit Achievement with ExcellenceDemonstrate understanding of bonding, structure, properties and energy changes.

Demonstrate in-depth understanding of bonding, structure, properties and energy changes.

Demonstrate comprehensive understanding of bonding, structure, properties and energy changes.

Check that the National Student Number (NSN) on your admission slip is the same as the number at the top of this page.

You should attempt ALL the questions in this booklet.

A periodic table is provided on the Resource Sheet L2–CHEMMR.

If you need more room for any answer, use the extra space provided at the back of this booklet and clearly number the question.

Check that this booklet has pages 2 – 21 in the correct order and that none of these pages is blank.

YOU MUST HAND THIS BOOKLET TO THE SUPERVISOR AT THE END OF THE EXAMINATION.

English translation of the wording on the front cover

te mātauranga matū, kaupae 2, 2015(g), ki te whakawera wai, e ai ki te hoahoa i raro. ka inea e...

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